In large-scale printing systems, printing ink is typically stored in a reservoir or ink supply comprising one or more bottle. During extended periods of stand-by or non-use of the printing system, such as over-night, weekends, or holiday periods, the ink may begin to separate into different component parts. In this regard, printing inks can be complex compositions and may include a dispersion of solid particles in a liquid mix comprising, for example, wax and/or a gelling agent. Separation of the components is problematic because it naturally has a direct impact upon the print quality.
For this reason, ink storage assemblies for printing systems have been developed which include mixing devices in the reservoir or ink supply to prevent separation of the ink into its different components and to maintain the ink in a well-mixed state. In this context, however, it has been found that known ink storage arrangements are sub-optimal in the efficiency and effectiveness of the mixing of the ink they hold. In particular, it will be appreciated that the ink held in the reservoir or ink supply should be mixed uniformly. This is not only critical to providing a fast start-up time for the printing system after a stand-by period or non-use period, but also for ensuring good print quality on the first and following printed media.